Bioactivities And Acaricidal Mechanism Of Plant Essential Oils To Tetranychus Cinnabarinus Boisduval (Acari:Tetranychidae)

The carmine spider mite, Tetranychus cinnabarinus Boisduval, is a severe pest ofvegetables, flowers, grass, trees, other economic crops and ornamental plants because of the high inbreeding reproductive potential and short life cycle, which impose high costs on greenhouse growers for control measures and the damage to crops. The purpose of this study was to evaluate the contact activities, the fumigation toxicities, oviposition-deterring activities and repellence activities of rosemary oil, zanthoxylum oil, patchouli oil, lavender oil and cinnamon oil against T.cinnabarinus as well as investigated the movement behaviors of T.cinnabarinus treated by the essential oils by using Ethovision XT6 video-tracking software. The main results were as follows:1. The highest FAO contact mortality of T.cinnabarinus was patchouli oil treatment, at 98.15%, followed by lavender oil treatment (97.41%) and cinnamon oil (90.00%), and the lowest is rosemary oil treatment (only 68.15%) at the concentration of 2%, after 72 h. The highest spray contact mortality of T.cinnabarinus was also patchouli oil treatment, at 100.00%, followed by lavender oil treatment (86.67%), and the lowest is cinnamon oil treatment (only 81.48%) at the concentration of 2%, after 48 h.2.The fumigation efficacy against T.cinnabarinus was increased with increased concentrations of the essential oils.The highest fumigation mortality of T.cinnabarinus was lavender oil treatment, at 99.26%, followed by cinnamon oil treatment (97.78%), and the lowest is zanthoxylum oil treatment (only 47.04%) at the dose of 2.5 ?L, after 48 h.The highest oviposition inhibition rate of T.cinnabarinus was rosemary oil treatment, at 98.50%, followed by lavender oil treatment (91.98%) and cinnamon oil treatment (86.01%), and the lowest is zanthoxylum oil treatment (only 75.85%) at the dose of 2.5 ?L, after 24 h.The highest oviposition inhibition index of T.cinnabarinus was lavender oil treatment, at 0.8531, followed by rosemary oil treatment (0.7523) and zanthoxylum oil treatment (0.4253), and the lowest is cinnamon oil treatment (only 0.3606) at the dose of 2.5 ?L, after 24 h.The highest repellence rate of T.cinnabarinus was rosemary oil treatment, at 98.44%, followed by lavender oil treatment (86.67%) and cinnamon oil treatment (75.56%), and the lowest is zanthoxylum oil treatment (only 70.00%) after 12 h.3. As can been seen from the experiment processes, the control T. cinnabarinus typically moved along the Petri dish wall, whereas the contaminated T. cinnabarinus remained predominantly in the center of the dish. Moreover, the mites treated by LCio displayed excitation and had the highest mobile frequency, and then with increasing concentration of patchouli oil and wormwood oil, the mobile frequency of treated mites showed downward trend and most of the treated mites moved slowly and few could change directions. When the concentration of essential oils was increased to LC30, the mites showed limb twitching and lack of coordination. With the extension of time, the mites gradually became quiescent.4. The mortality of female adults and the rate of oviposition-deterringwere positively correlated with the test concentrations after 24 h, and their LC50 values were 0.599 and 0.624%, respectively. Moreover, with the increasing of test concentration, the contact activity was enhanced, viposition inhibition rate and index were showed an increasing tendency and the response of female adults is more stronger than eggs. Protease and POD were activated, SOD activity was inhibited with different doses after 4 h. Protease activation rates were 10.96,47.70 and 62.92%, respectively; POD activities were 2.3,1.5 and 0.3 times of the control, respectively; SOD inhibition rates were 44.52,23.91 and 49.08%, respectively. CAT was activated at LC30 and LC50, the activation rates were 20.26 and 52.22%, respectively; After LC90 treatment CAT activity was inhibited, the inhibition rate was 62.21%.5. The microemulsion of CremopHor EL-40 as surfactant, anhydrous ethanol as co-surfactant has the better microemulsion ability.